Gel electrophoresis apparatus

ABSTRACT

A gel electrophoresis apparatus for receiving a gel cassette is adapted to receive the gel cassette inclined to such an extent that the upper edge of the gel can be seen at an angle from above through the liquid surface in the upper buffer container.

TECHNICAL FIELD

The present invention relates to an arrangement in a gel electrophoresisapparatus for receiving a gel package, usually called a gel cassette.

BACKGROUND OF THE INVENTION

In gel electrophoresis apparatuses known so far, the gels are receivedeither vertically or horizontally, i.e. the gels either stand upright inthe gel electrophoresis apparatuses or lie horizontally in the gelelectrophoresis apparatuses. Usually, the necessary electrophoresisbuffer is provided from two connecting liquid tanks or buffercontainers, thus for a vertical gel an upper and a lower buffercontainer.

A disadvantage of receiving a gel in a gel cassette vertically in a gelelectrophoresis apparatus is that the working position for the personwho loads the gel with samples is very uncomfortable in that therefraction of light in the glass plates of the gel cassette makes itvery difficult to clearly see the gel edge without placing one's eyesclosely by the gel cassette at the same time as the pipette with whichthe wells are loaded, has to be brought up above eye-level in order forthe samples to be applied in a correct manner into the wells without thepipette tip contacting and damaging the gel. Neither is it possible toinstead look at the gel edge straight from above through the liquidsurface in the upper buffer container to which the gel cassette isconnected, since the vertical position of the pipette tip in relation tothe gel edge can then not be determined.

The disadvantage of horizontally mounted gels is that present systemsfor loading of samples restrict the resolution which is the reason whyhorizontal systems cannot be used when a high resolution is required.

EP-A-339 975 discloses a gel electrophoresis apparatus where the gelcassette is inclined between 5° and 10° relative to the vertical plane.The purpose of the inclination is to facilitate the handling of theapparatus in that the inclination prevents the gel cassette from tippingwhen it is being clamped to the electrophoresis apparatus. The abovedifficulty of clearly seeing the gel edge is neither mentioned norovercome by means of this inclination.

SUMMARY OF THE INVENTION

The object of the present invention is to bring about a gelelectrophoresis apparatus at which the working position for a user,primarily the person who loads the gel with samples, will be much morecomfortable in comparison with the working position at gelelectrophoresis apparatuses with vertical gel known so far.

This is attained, mainly, in that the gel electrophoresis apparatus isadapted to receive the gel cassette inclined to such an extent that theupper edge of the gel can be seen through the liquid surface of theupper buffer container.

Hereby, the working position for the person who loads the gel will bemuch improved in comparison with the conditions at a gel in an uprightposition in that both the pipette tip and the gel edge will be clearlyvisible at an angle from above through the liquid surface in the upperbuffer container, and, consequently, the pipette does not have to bebrought above eye-level in connection with the loading of the samples.

The necessary inclination of the gel cassette in relation to thevertical plane for this to be achieved is normally about 15° or greater,e.g. in the range of 15° to 30°. With a smaller inclination, such as inthe above-mentioned EP-A-339 975, or with a completely vertical gel,light refraction phenomena in the liquid surface makes it impossible tosee and estimate the distance to the upper edge of the gel through theliquid surface.

In addition to the working position thus being better when one can lookfrom above during the sample application, several further advantages areattained, such as that the upper liquid tank (buffer container) can bemade of a non-transparent material and can be mounted to the operatorside of the gel package which leads to greater freedom in theconstruction.

BRIEF DESCRIPTION OF THE DRAWING

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingwhich is given by way of illustration only, and thus is not limitativeof the present invention, and wherein:

The figure is a schematic perspective view of an embodiment of a gelelectrophoresis apparatus according to the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT

The gel electrophoresis apparatus shown comprises a stand 1 forreceiving and supporting a gel cassette 2. The stand 1 of the gelelectrophoresis apparatus receives the gel cassette 2 with an upper partof the gel cassette 2 leaning away from a user relative to a verticalplane. The stand 1 supports the gel cassette 2 at an inclined angle ofabout 15° or greater with respect to a vertical plane such that theupper part of the gel cassette 2 leans away from a user. The inclinationof the gel cassette 2 is preferably in the range of 15° to 30° withrespect to the vertical plane.

The stand 1 is provided with a pair of pins 3 which cooperate withrecesses or openings 4 in the gel cassette 2 so that the gel cassette 2can be hung on the pins 3 of the stand 1. As shown in FIG. 1, when thegel cassette 2 is hung on the pins 3 of the stand 1, the gel cassette 2rests against the stand 1. Thus, the stand 1 supports the gel cassette2. Further, as set forth above, the stand 1 supports the gel cassette 2such that the upper part of the gel cassette 2 leans away from a user atan inclined angle preferably in the range of 15° to 30°.

In this connection, it should be noted that, as an alternative, the gelcassette could lean towards a user.

In a manner known per se, the gel cassette 2 comprises two glass plates(not shown) between which a gel (not shown), e.g. for nucleic acidseparation, is cast.

The lower part of the gel cassette 2 is, in a manner known per se,received in a lower buffer container 5, while an upper buffer container6, necessary for an electrophoresis run, in the illustrated case inaccordance with the invention is fixed to that glass plate of the gelcassette 2 which faces away, or is spaced further away, from the stand1.

To keep the gel cassette 2 in a fixed position against the stand 1, twoschematically illustrated brackets 7 are provided, which preferably arespring-loaded in a manner not shown more in detail for biasing thebrackets 7 against the gel cassette 2, to thereby bias the gel cassette2 against the stand 1.

In the embodiment shown, the gel cassette is temperature regulated inthat a further plate is provided on the glass plate of the gel cassette2 which faces away from the stand 1, for forming an interspace betweenthese plates, through which interspace temperature regulated watercirculates from a schematically shown inlet 8 to an outlet which is notshown on the drawing.

According to the invention, the spring-loaded brackets 7 include tubesto be connected to the inlet means 8 and outlet means (not shown) of thegel cassette 2.

Electrodes (not shown), necessary for carrying out an electrophoresisrun, are in accordance with the invention provided with brackets (notshown) to make it possible to hang the electrodes in the upper and lowerbuffer containers 6 and 5, respectively.

To protect the respective electrode and prevent the buffer liquid in thebuffer containers 5 and 6 from being contaminated, each buffer container5 and 6 is provided with a lid (not shown). In accordance with theinvention, the respective electrode may be integrated in the respectivelid. Moreover, the lids reduce the evaporation of buffer liquid from thebuffer containers during a run which is of great advantage since,without lids, the evaporation can be so extensive that the separationresult deteriorates.

As should be understood, the working position for a person who loads thegel with samples will be considerably improved with an inclined gelcassette as above in comparison with an upright standing gel cassette,mainly since the person who loads the samples will be able to clearlysee the gel edge through the liquid surface in the upper buffercontainer due to the refraction of light in the buffer liquid surface.

The invention is, of course, not restricted to the embodiment describedabove and shown in the drawing, but many changes and modifications canbe made within the scope of the general inventive concept as defined inthe following claims.

We claim:
 1. A gel cassette electrophoresis apparatus comprising:a standfor receiving a gel cassette therein, said stand supporting said gelcassette at an inclined angle of about 15° or greater with respect to avertical plane passing through said stand; and an upper buffer containerlocated on an upper portion of said stand for receiving a buffer liquidtherein, wherein an upper edge of a gel located in said gel cassette isvisible through a liquid surface of said buffer liquid in said upperbuffer container due to said inclined angle of said gel cassette.
 2. Thegel cassette electrophoresis apparatus according to claim 1, furthercomprising:at least one suspension pin located on said stand forcooperating with a recess provided on said gel cassette; and at leastone bracket located on said stand, said bracket including a spring forbiasing said bracket against said gel cassette, to thereby bias the gelcassette against said inclined support surface.
 3. The gel cassetteelectrophoresis apparatus according to claim 1, wherein the inclinationof the gel cassette is in the range of 15° to 30° with respect to thevertical plane.
 4. The gel cassette electrophoresis apparatus accordingto claim 1, wherein the gel cassette comprises first and second glassplates, the first glass plate being spaced apart from said second glassplate, and wherein the upper buffer container of the gel electrophoresisapparatus is fixed to the first glass plate.
 5. The gel cassetteelectrophoresis apparatus according to claim 1, further comprising alower buffer container for receiving the lower part of the gel cassette,wherein electrodes, necessary for carrying out a gel electrophoresisrun, are provided with brackets for hanging the electrodes in the upperand lower buffer containers, respectively.
 6. The gel cassetteelectrophoresis apparatus according to claim 5, wherein the respectiveelectrode is integrated in a lid designed for the respective buffercontainer.
 7. The gel cassette electrophoresis apparatus according toclaim 1, wherein the gel electrophoresis apparatus receives the gelcassette with its upper part leaning away from a vertical planeextending through a lower part of said gel cassette.
 8. The gel cassetteelectrophoresis apparatus according to claim 1, wherein brackets areprovided to keep the gel cassette against said stand.
 9. The gelcassette electrophoresis apparatus according to claim 8, wherein the gelcassette comprises inlet and outlet means for water totemperature-regulate the gel cassette by circulation of said water, andwherein said brackets include tubes to be connected to said inlet andoutlet means of the gel cassette.
 10. The gel cassette electrophoresisapparatus according to claim 8, wherein said brackets are spring-loaded.11. The gel cassette electrophoresis apparatus according to claim 10,wherein the gel cassette comprises inlet and outlet means for water totemperature-regulate the gel cassette by circulation of said water, andwherein said brackets include tubes to be connected to said inlet andoutlet means of the gel cassette.
 12. The gel-cassette electrophoresisapparatus according to claim 1, wherein said stand includes suspensionpins for cooperation with recesses provided on the gel cassette forhanging the gel cassette on said stand.
 13. The gel cassetteelectrophoresis apparatus according to claim 12, wherein brackets areprovided to keep the gel cassette against said stand.
 14. The gelcassette electrophoresis apparatus according to claim 13, wherein saidbrackets are spring-loaded.
 15. The gel cassette electrophoresisapparatus according to claim 14, wherein the gel cassette comprisesinlet and outlet means for water to temperature-regulate the gelcassette by circulation of said water, and wherein said brackets includetubes to be connected to the inlet and outlet means of said gelcassette.